Isolation levels And The Twist

Three isolation levels is what we have seen already:

1. No isolation — chaos, everyone reads and writes whatever, wherever, whenever.
2. Full isolation — serial execution. Transactions line up and take turns like it's the DMV.
3. Read committed — you only see what's already been committed, even if the transaction next to you has five operations in flight.

Feels like enough, right? Wrong. The world of bugs is a very rich ecosystem, and it just evolved a new species for you.